1. Field of the Invention
The present invention relates to an electric actuator, which causes a displacement member to be moved by transmitting a drive force of a driving section to the displacement member through a feed screw.
2. Description of the Related Art
Heretofore, as a means for transporting a workpiece or the like, electric actuators have widely been known, in which a feed screw is driven rotatably by the rotary drive force of a rotary drive source such as a motor or the like, and a slider that transports the workpiece is displaced thereby.
With this type of electric actuator, for example, as disclosed in Japanese Laid-Open Patent Publication No. 09-144830, a table is disposed for displacement along a guide rail, and a drive source is disposed in parallel to the guide rail, the drive source being connected to a support plate disposed on one end of the guide rail through a bracket. In addition, the drive (rotative) force output from the drive source is transmitted to a screw shaft, which is disposed inside the guide rail, through a drive pulley, a driven pulley and a toothed belt, which collectively constitute a force transmission mechanism. Then, the screw shaft is rotated, and a nut member screw-engaged with the screw shaft is displaced along the axial direction. Further, along therewith, a table, which is connected to a nut member, is displaced along the guide rail.
Incidentally, in the conventional technique according to Japanese Laid-Open Patent Publication No. 09-144830, the guide rail including the table and the drive source that generates a drive force for displacing the table are disposed in parallel, and further, are mutually connected together through the bracket, which is provided separately from the guide rail. Owing thereto, the number of parts required to construct the electric actuator increases, inviting an increase in production costs and the number of assembly steps, and the apparatus itself becomes larger in scale.
Recently, due to constraints imposed on the usage environment for electric actuators, the equipment installation space and the like, there have been demands for an electric actuator having a low profile, in which the height dimension of the electric actuator is suppressed.